Artificial asteria



June 13, i950 R. s. MUKAH 25H51@ ARTIFICAL ASTERIAE Filed Feb. 5, 1948 M M /CM ATTORNEYS Patented June 13, 1950 UNITED STATESPATENT OFFICE 2 Claims.

This invention relates to articial asteriae and i to means for artificially producing asterism in gem stones.

In using the expression gem stones I do not limit myself to the commonly accepted meaning, L, that is, a natural stone of large intrinsic value;

. 2 Fig. 1 is a side elevation of a cabochon-cut stone, and

has been proposed, for example, to create asterism by cementing a specially treated reflective backing to the rear base of a synthetic cabochon-cut stone or by grinding a concavity in the back of such a stone and actually cutting the outline of a star into the rear wall of the stone. None of these attempts has been well received; the resulting asterism is flat and dead, and is so patently and recognizably artificial that people generally are reluctant to wear stones which have been so treated.

My process, which I have derived after extensive research and experimentation, may be employed to produce asterism in any hard, transparent or translucent material which is capable of reflecting light, without resorting to doublets, as compound stones are known, and without noticeably cutting or otherwise disguring the stone itself. A genuine stone may be asteriated by my method Without danger of damaging or disguring it. Owners of genuine cabochon rubies, Sapphires, or other stones may at small cost increase the intrinsic value of the gem by having them asteriated.

My invention may be practiced on any Cabochon-cut stone, natural, synthetic, or articial, regardless of the size or shape; and will produce a star which is visible not only from above, but from all sides of the stone.

It is an object of the invention therefore to provide an improved method of artificially producing asterism.

It is a still further object of the invention to provide means for stimulating the natural asterism of certain gem stones, without disguring the stone or requiring extensive grinding, polishing, or cutting operations.

Other features and advantages will hereinafter appear.

In the accompanying drawings;

Fig. 2 is a base plan view of the same after the asterism treatment has been applied thereto.

Figs. 3 and 4 are respectively a side elevation and a base plan view of a double cabochon stone treated in slightly dllferent manner to produce asterism.

Fig. 5 is a side elevation, partly in section, and enlarged to show details of one means of practicing my invention.

Fig. 6 is a partial base plan view of a stone treated in a third manner to produce asterism, and

Fig. '7 is a perspective of a stone treated in any of the above enumerated ways and indicating the appearance of the asteria therein.

Referring now to Fig. 1 the Cabochon-cut stone li! has a plane base Il. The stone and base may be finely ground and polished; that is, there is usually no need for further grinding or polishing after the asterism-producing step. "I'hev stone l!! may be set in cement I2 on a dop stick I4 for support. Then, using means such as the cylindrical iron bar l5 suitably held in a rotating chuck i6 and ne gem-polishing dust, the base l i is given a great multiplicity of minute, sharp, shallow cuts or grooves over the three intersecting areas I1. Three areas of engraving intersecting as shown in Fig. 2 will produce a sixrayed star. This is the desired treatment because it simulates the asterism oi. a natural gem. The individual cuts or engravings are short and may be considered to be substantially parallel one with the other. The individual cuts should extend at an angle, preferably a right angle, with respect to the radii of the back of the stone.

In the Fig. 3 embodiment the stone 2a has a double cabcchon-cut in that the base 2| is also convex. A somewhat different pattern of engraving has been employed, as will be noted; the respective engraved areas l1' are wider at the girdle than at the center of the base. Preferably said areas are not truly triangular in that there is no clearly dened apex. 'I'he asterism thus produced is also characterized by a bright center and well-defined luminous rays. In the Fig. 6 embodiment the entire base is lightly engraved. The resulting individual cuts are arcuate, intersecting the radii of the base. These individual lines of engraving are not necessarily concentric; in fact a somewhat irregular pattern often produces superior luminosity in the stan It will be understood that Fig. 6 shows a portion only,

of the stone 3i), and that but one sector I1" thereof has been treated.

The engravings or markings of the forms of Figs. 3 and 6 are perhaps best accomplished by holding the rod l5 at an angle as shown in dotdash lines of Fig. 5. A vibrating tool, rather than a rotating tool, may be employed, and other mechanical expedients will suggest themselves to the skilled lapidary.

It should be understood that the respective gures exaggerate the prominence of the engraved areas. In fact the individual lines of en-n graving are exceedingly fine and when the stone is viewed under indirect light are hardly discernible.

The asterism is produced by the reection of rays of direct light from the multitudinous facets or side walls of the engraved lines. A feature of asteriae produced by my method is that the stars thereof seem to move within the stone as the stone and light source are moved relative to each other. The star therefore has realism has not, to my knowledge, been obtained by any other method. Fig. '7, illustrates the appearance 0i the stone when the stone is viewed from above, under direct light.v

Thus, among others, the several objects oi the invention as aiore noted are achieved. Obviously numerous changes construction and rearrangement of the parts might be resorted to Without departing from the spirit of the invention as dened by the claims.

I claim:

1. An articial asteria in a body of hard transparent material cut en Cabochon to form a rear surface comprising a lplurality of relatively narrow radially extending areas on said rear surface substantially free from short minute separate grooves parallel to the radii of said rear surface, a multiplicity of short closely spaced minute separate grooves formed in said relatively narrow radially extending areas, said short grooves being solely substantially perpendicular to the radii of said rear surface and to the long dimension of said radially extending areas, and a plurality of relatively broad radially extending areas on said rear surface interposed between and separating said relatively narrow grooved areas.

2. An artificial asteria in a body of hard transparent material cut en Cabochon to form a rear surface comprising a plurality of relatively narrow radially extending areas on said rear surface substantially free from short minute separate grooves parallel to the radii of said rear surface, a multiplicity of short closely spaced minute separate grooves formed in said relatively narrow radially extending areas, said l short grooves being solely substantiallyT perpendicular to the radii of said rear surface and to the lon-g dimension of said radially extending areas, and a plurality of relatively broad radially extending areas on said rear surface of said geni substantially free from all short minute grooves and separating said relatively narrow grooved areas.

RALPH S. MUKAI,

REFERENCES CITED The following references are of record in the die of this patent:

UNITED STATES PA'IENTS Number Name Date 577,440 Lutton Feb. 23, 187

2,081A83 Haltom May 25, 1935 2,090,240 Strothman Aug. 17, 1937 

